In printing, duplicating and like machines, copy sheets are fed seriatum over a conveyor board to a printing couple wherein images are duplicated on one or both sides of the sheet. In some machines, such as offset lithographic duplicating machines, the printing couple includes a number of rollers or cylinders, such as a master cylinder, a blanket cylinder and an impression cylinder. The cylinders are aligned in precise parallel relationship for high resolution of the images on the copy sheets. The copy sheets, themselves, must be fed into the printing couple in precise registration. Otherwise, the images will not be "square" with the copy sheets.
Each sheet is registered prior to being fed into the printing couple such that its leading edge is parallel to the axes of the printing couple cylinders. Conventionally, this is accomplished by some form of stop means for engaging the sheets as they move over the conveyor board, immediately prior to entering the printing couple, with the stop means being parallel to the cylinder axes.
In addition, each copy sheet must be registered laterally of the direction of movement, i.e. in a side-to-side direction, so that the copy sheets are centered as they are fed through the printing couple. This often is accomplished by a mechanism that conventionally is called a pull guide mechanism. Such devices literally grasp each copy sheet and pull the copy sheet laterally against a side stop which is in proper registration or alignment with the printing couple.
Such pull guide mechanisms often are quite complicated. They must be adjustable to accommodate different sizes and weights of copy paper as well as to adjust the pull guide mechanism for coordination with the other registration means and cylinders of the machine which, themselves, most often are adjustable.
This invention is directed to such pull guide mechanisms and, generally, to solving the continuing problem of providing a simplified and easily and accurately adjustable device.